/Engine/Plugins/Runtime/GameplayAbilities/Source/GameplayAbilities/Public/GameplayEffectAggregator.h
This will be deprecated/removed soon with the transition to struct-based attributes.
If possible, the base value from the reverse evaluation. If not possible, the original final value is returned.
float ReverseEvaluate ( float FinalValue, const [FAggregatorEvaluateParameters](API\Plugins\GameplayAbilities\FAggregatorEvaluateParameters) & Parameters ) const